Radiation imaging apparatus and radiation imaging system

Abstract

A radiation imaging apparatus is provided. The apparatus comprises pixels arranged in an image sensing region, a first and a second detecting elements configured to obtain radiation irradiation information, a first signal line to which a signal from the first detecting element is to be output and a second signal line to which a signal from the second detecting element is to be output, and a signal processing circuit configured to process the signals output from the first and the second detecting elements. The first the second signal lines are arranged in the image sensing region or arranged adjacent to the image sensing region, the first detecting element has a larger region to detect radiation than the second detecting element. The signal processing circuit generates the radiation irradiation information based on the signals from the first and the second signal lines.

The invention claimed is: 
     
       1. A radiation imaging apparatus comprising:
 a plurality of pixels arranged in an array in an image sensing region and configured to obtain a radiation image corresponding to a radiation irradiation dose; 
 at least one first detecting element and at least one second detecting element each including a conversion element configured to convert radiation into an electrical signal; 
 the first detecting element and the second detecting element configured to obtain radiation irradiation information corresponding to radiation irradiated to the radiation imaging apparatus, including at least one of start of radiation irradiation, end of radiation irradiation, a radiation irradiation intensity, or a radiation irradiation dose; 
 a first signal line to which an electrical signal from the first detecting element is configured to be output and a second signal line to which an electrical signal from the second detecting element is configured to be output; and 
 a signal processing circuit configured to process the electrical signal output from the first detecting element via the first signal line and the electrical signal output from the second detecting element via the second signal line, wherein 
 the radiation irradiation information is information different from the radiation image, 
 the first signal line and the second signal line are arranged in the image sensing region or arranged adjacent to the image sensing region, 
 a sensitivity of the second detecting element to convert radiation into an electrical signal is lower than that of the first detecting element, and 
 the signal processing circuit generates the radiation irradiation information based on a difference between the electrical signal from the first signal line and the electrical signal from the second signal line. 
 
     
     
       2. The apparatus according to  claim 1 , wherein a region to detect radiation of the first detecting element is larger than that of the second detecting element, the first detecting element and the second detecting element are arranged in the image sensing region. 
     
     
       3. The apparatus according to  claim 1 , further comprising a scintillator configured to convert radiation into light,
 the conversion element is configured to convert the light into the electrical signal, and 
 the second detecting element includes, between the scintillator and the conversion element of the second detecting element, a shielding member that shields the light. 
 
     
     
       4. The apparatus according to  claim 1 , wherein the conversion element of the first detecting element and the conversion element of the second detecting element have the same structure. 
     
     
       5. The apparatus according to  claim 1 , wherein the first detecting element includes a first switch element between the conversion element of the first detecting element and the first signal line, and
 the second detecting element includes a second switch element between the conversion element of the second detecting element and the second signal line. 
 
     
     
       6. The apparatus according to  claim 5 , wherein the first switch element and the second switch element have the same structure. 
     
     
       7. The apparatus according to  claim 1 , wherein the conversion element of the first detecting element and the first signal line are directly connected, and
 the conversion element of the second detecting element and the second signal line are directly connected. 
 
     
     
       8. The apparatus according to  claim 1 , wherein the number of the first detecting elements to be connected to the first signal line is equal to the number of the second detecting elements to be connected to the second signal line. 
     
     
       9. The apparatus according to  claim 1 , wherein the first signal line and the second signal line each include a region that overlaps a part of the plurality of pixels, the first detecting element and the second detecting element in planar view with respect to the image sensing region, and
 a sum of the number of pixels in the plurality of pixels that overlap the first signal line, the numbers of first detecting elements that overlap the first signal line, and the numbers of second detecting elements that overlap the first signal line is equal to a sum of the number of pixels the plurality of pixels that overlap the second signal line, the numbers of first detecting elements that overlap the second signal line, and the numbers of second detecting elements that overlap the second signal line. 
 
     
     
       10. The apparatus according to  claim 1 , further comprising a plurality of image signal lines to which electrical signals from the plurality of pixels are to configured to be output, and
 at least one image signal line out of the plurality of image signal lines also serves as the first signal line or the second signal line. 
 
     
     
       11. The apparatus according to  claim 1 , further comprising a plurality of image signal lines to which electrical signals from the plurality of pixels are configured to be output. 
     
     
       12. The apparatus according to  claim 1 , wherein the signal processing circuit controls a radiation source by using the radiation irradiation information. 
     
     
       13. A radiation imaging system, comprising:
 a radiation imaging apparatus according to  claim 1 ; and 
 a signal processing unit configured to process a signal from the radiation imaging apparatus. 
 
     
     
       14. A radiation imaging apparatus, comprising:
 a plurality of pixels arranged in an array in an image sensing region and configured to obtain a radiation image; 
 a first detecting element and a second detecting element each including a conversion element configured to convert radiation into an electrical signal, being for obtaining radiation irradiation information, corresponding to radiation irradiated to the image sensing region, including at least one of start of radiation irradiation, end of radiation irradiation, a radiation irradiation intensity, or a radiation irradiation dose; 
 a signal processing circuit configured to process a first electrical signal output from the first detecting element and a second electrical signal output from the second detecting element, wherein 
 the radiation irradiation information is information different from the radiation image, 
 a sensitivity of the second detecting element to convert radiation into an electrical signal is lower than that of the first detecting element, and 
 the signal processing circuit generates the radiation irradiation information based on a difference between the first electrical signal and the second electrical signal. 
 
     
     
       15. The apparatus according to  claim 14 , wherein the first detecting element and the second detecting element are arranged in the image sensing region. 
     
     
       16. The apparatus according to  claim 14 , further comprising a scintillator configured to convert radiation into light,
 the conversion element is configured to convert the light into the electrical signal, and 
 the second detecting element includes, between the scintillator and the conversion element of the second detecting element, a shielding member that is configured to shield the light such that a region for detecting the radiation is smaller than the first detection element to cause the sensitivity of the second detecting element to convert radiation into an electrical signal is lower than that of the first detecting element. 
 
     
     
       17. The apparatus according to  claim 14 , wherein the conversion element of the first detecting element and the conversion element of the second detecting element have the same structure. 
     
     
       18. The apparatus according to  claim 14 , wherein the first detecting element includes a first switch element between the conversion element of the first detecting element and a first signal line to which the first electrical signal from the first detecting element is to be output, and
 the second detecting element includes a second switch element between the conversion element of the second detecting element and a second signal line to which the second electrical signal from the second detecting element is to be output. 
 
     
     
       19. The apparatus according to  claim 18 , wherein the first switch element and the second switch element have the same structure. 
     
     
       20. The apparatus according to  claim 18 , wherein the number of the first detecting elements to be connected to the first signal line is equal to the number of the second detecting elements to be connected to the second signal line. 
     
     
       21. The apparatus according to  claim 18 , wherein the first signal line and the second signal line each include a region that overlaps a part of the plurality of pixels, the first detecting elements and the second detecting elements in planar view with respect to the image sensing region, and
 a sum of the number of pixels in the plurality of pixels that overlap the first signal line, the numbers of first detecting elements that overlap the first signal line, and the numbers of second detecting elements that overlap the first signal line is equal to a sum of the number of pixels in the plurality of pixels that overlap the second signal line, the numbers of first detecting elements that overlap the second signal line, and the numbers of second detecting elements that overlap the second signal line. 
 
     
     
       22. The apparatus according to  claim 18 , further comprising a plurality of image signal lines to which electrical signals from the plurality of pixels are to be output, and
 at least one image signal line out of the plurality of image signal lines also serves as the first signal line or the second signal line. 
 
     
     
       23. The apparatus according to  claim 18 , further comprising a plurality of image signal lines to which electrical signals from the plurality of pixels are to be output. 
     
     
       24. The apparatus according to  claim 14 , wherein the conversion element of the first detecting element and a first signal line to which the first electrical signal from the first detecting element is to be output are directly connected, and
 the conversion element of the second detecting element and a second signal line to which the second electrical signal from the second detecting element is to be output are directly connected. 
 
     
     
       25. The apparatus according to  claim 14 , wherein the signal processing circuit controls a radiation source by using the radiation irradiation information. 
     
     
       26. A radiation imaging system, comprising:
 a radiation imaging apparatus according to  claim 14 ; and 
 a signal processing unit configured to process a signal from the radiation imaging apparatus. 
 
     
     
       27. A radiation imaging apparatus, comprising:
 a plurality of pixels arranged in an array in an image sensing region and configured to convert light converted from radiation by a scintillator into an electrical signal to obtain a radiation image; 
 a first photoelectric conversion element and a second photoelectric conversion element configured to convert light converted by the scintillator into an electrical signal, being for obtaining radiation irradiation information, corresponding to radiation irradiated to the image sensing region, including at least one of start of radiation irradiation, end of radiation irradiation, a radiation irradiation intensity, or a radiation irradiation dose; 
 a signal processing circuit configured to process a first electrical signal output from the first photoelectric conversion element and a second electrical signal output from the second photoelectric conversion element, wherein 
 the radiation irradiation information is information different from the radiation image, 
 a region of the second photoelectric conversion element for detecting the radiation is smaller than that of the first detection element by a shielding member that is arranged between the scintillator and the second photoelectric conversion element and shields the light converted by the scintillator, and a sensitivity of the second photoelectric conversion element to convert radiation into an electrical signal is lower than that of the first photoelectric conversion element, and 
 the signal processing circuit generates the radiation irradiation information based on a difference between the first electrical signal and the second electrical signal. 
 
     
     
       28. A radiation imaging system, comprising:
 a radiation imaging apparatus according to  claim 27 ; and 
 a signal processing unit configured to process a signal from the radiation imaging apparatus.